Add mojo interface+impl creation of audio streams.

content/browser/BUILD.gn

Index: content/browser/BUILD.gn
diff --git a/content/browser/BUILD.gn b/content/browser/BUILD.gn
index 9e3a53a3141d0a6903788e9d30c763e6764ce9ba..c1fd6eff95c14ecc40da3b9de5cae1dcbc644b1a 100644
--- a/content/browser/BUILD.gn
+++ b/content/browser/BUILD.gn
@@ -96,6 +96,7 @@ source_set("browser") {
     "//media/midi",
     "//media/midi:mojo",
     "//media/mojo/interfaces",
+    "//media/mojo/services",
     "//mojo/common",
     "//mojo/edk/system",
     "//mojo/public/cpp/bindings",
@@ -1147,6 +1148,9 @@ source_set("browser") {
     "renderer_host/media/audio_output_authorization_handler.h",
     "renderer_host/media/audio_output_delegate_impl.cc",
     "renderer_host/media/audio_output_delegate_impl.h",
+    "renderer_host/media/audio_output_stream_factory_context.h",
+    "renderer_host/media/audio_output_stream_factory_context_impl.cc",
+    "renderer_host/media/audio_output_stream_factory_context_impl.h",
     "renderer_host/media/audio_renderer_host.cc",
     "renderer_host/media/audio_renderer_host.h",
     "renderer_host/media/audio_sync_reader.cc",
@@ -1167,6 +1171,8 @@ source_set("browser") {
     "renderer_host/media/media_stream_track_metrics_host.h",
     "renderer_host/media/media_stream_ui_proxy.cc",
     "renderer_host/media/media_stream_ui_proxy.h",
+    "renderer_host/media/render_frame_audio_output_stream_factory.cc",
+    "renderer_host/media/render_frame_audio_output_stream_factory.h",
     "renderer_host/media/video_capture_controller.cc",
     "renderer_host/media/video_capture_controller.h",
     "renderer_host/media/video_capture_controller_event_handler.h",
@@ -1908,10 +1914,6 @@ source_set("browser") {
     ]
   }
 
-  if (enable_mojo_media) {
-    deps += [ "//media/mojo/interfaces" ]
-  }
-
   if (use_aura) {
     deps += [
       "//services/ui/public/cpp",